MICROLITHOGRAPHIC PROJECTION EXPOSURE APPARATUS AND METHOD FOR VARYING AN OPTICAL WAVEFRONT IN A CATOPTRIC LENS OF SUCH AN APPARATUS

摘要

A microlithographic projection exposure apparatus (10) for projecting a reflective mask (14) onto a light-sensitive layer (16) contains a catoptric lens (26) comprising a plurality of mutually adjusted mirrors (M1 to M6) configured to reflect projection light having a center wavelength of between 5 nm and 30 nm. The lens (26) is configured to direct projection light reflected from the mask (14) onto the light-sensitive layer (16). At least one of the plurality of mirrors (M2, M3) is a correction mirror for correcting wavefront deformations, which changes its form permanently when it is processed by a processing beam (65). Furthermore, a processing device (42) is provided, having a processing head (44), from which the processing beam (65) emerges during operation of the processing head. The processing head is arranged or can be arranged within the lens (26) such that the processing beam (65) impinges on none of the other plurality of mirrors before it processes the correction mirror (M2, M3).